Anticoagulation in Atrial Fibrillation Associated With Cardiac Amyloidosis: A Narrative Review

Cardiac amyloidosis (CA) involves the abnormal deposition and accumulation of amyloid proteins in the heart muscle. A hallmark of disease progression is declining heart function, which can lead to structural irregularities, arrhythmias, and ultimately heart failure. Atrial fibrillation (AF) is the most common arrhythmia that presents in CA patients, and this arrhythmia is significant because it can moderately increase the risk of patients developing intracardiac thrombi, thereby putting them at risk for thromboembolic events. The management of this complication entails the use of anticoagulants like vitamin K antagonists and direct oral anticoagulants to reduce the risk of thrombus formation. This article seeks to review AF in CA and the use of anticoagulation therapy for the management and reduction of thromboembolic risk. The major conclusions of this review are centered around the need for safe administration of anticoagulant therapy to CA patients, regardless of their CHA2DS2-VASc risk score. This review highlights the importance of taking a multidisciplinary or collaborative approach to CA treatment to ensure that all aspects of this multifaceted disease can be properly managed while minimizing adverse events like bleeding risk and drug-drug interactions.

Adherence, persistence and switching rates of apixaban, dabigatran and rivaroxaban in non-valvular atrial fibrillation: a multicentre real-life analysis at 3 years

INTRODUCTION

Adherence to and persistence with long-term treatment with oral anticoagulants play a significant role in preventing adverse events and mortality in patients with cardiac conditions. The aim of this study was to evaluate the adherence, persistence and switching rate at 3 years in real-life patients with non-valvular atrial fibrillation receiving treatment with first-line new oral anticoagulants.

METHODS

The study assessed all patients treated with drugs with the ATC codes B01AA, B01AE, B01AF and dispensed in pharmacies in the Lanciano-Vasto-Chieti and Pescara Local Health Units from 1 January 2011 to 30 September 2021. Adherence was calculated as the proportion of days covered; persistence was calculated as the difference in days between the start and end of treatment; and the switching rate was calculated as the difference in days between the start of treatment and the switch.

RESULTS

A total of 4270 patients were analysed. The absolute adherence figure at 3 years was 0.85. The lowest adherence levels were found in patients treated with dabigatran with an absolute value of 0.72, while the highest levels were found in patients treated with rivaroxaban with an absolute value at 3 years of 0.88. The persistence curves at 3 years of treatment with dabigatran showed a statistically significant difference (p<0.0001) compared with those of rivaroxaban and apixaban.

CONCLUSIONS

The data collected over a 3-year period showed that adherence and persistence levels and switch data were optimal and comparable in patients with non-valvular atrial fibrillation receiving treatment with either rivaroxaban or apixaban. In contrast, patients treated with dabigatran had worrying adherence and persistence levels.

Heterogeneous distributions in clinical events preceding anticoagulant treatment nonpersistence in patients with venous thromboembolism stratified by active cancer: A nationwide cohort study

BACKGROUND

Nonpersistence in anticoagulation therapy is common and associated with undesirable clinical outcomes in patients with venous thromboembolism (VTE).

METHODS

We investigated preceding clinical events of treatment nonpersistence (e.g., switching, discontinuing, or restarting) in VTE patients with and without active cancer using Korean claims database.

RESULTS

Clinically significant events including thromboembolic events, hepatic function change and surgery preceded treatment nonpersistence, but heterogeneous distributions of clinical events were observed in the presence of active cancer. Patients with active cancer had a low rate of clinical events preceding treatment nonpersistence, and new active cancer diagnosis in the nonactive cancer group was most common before the switch to parenteral anticoagulants from warfarin or non-vitamin K antagonist oral anticoagulants (NOACs).

CONCLUSION

These findings suggest that clinically significant events can precede treatment nonpersistence and largely paralleled current guidelines for patients with VTE, whereas heterogeneous distributions of clinical events were observed in the presence of active cancer.

Effectiveness and safety of oral anticoagulants for non-valvular atrial fibrillation: a population-based cohort study in primary healthcare in Catalonia

Objectives: Our objective was to analyse effectiveness and safety of oral anticoagulants (OAC) for stroke prevention in non-valvular atrial fibrillation. Material and methods: Population-based cohort study including adults initiating oral anticoagulants, either direct oral anticoagulants (DOAC) or vitamin K antagonists (VKA), during 2011-2020. Data source: SIDIAP, capturing information from the electronic health records of Primary Health Care in Catalonia, Spain. Study outcomes: stroke, cerebral and gastrointestinal (GI) haemorrhage, assessed by patients' subgroups according to different clinical characteristics. Results: We included 90,773 patients. Male sex, older than 75, previous event, peripheral artery disease, deep vein thrombosis, or receiving antiplatelets, antidiabetics or proton pump inhibitors (PPI) was associated with higher stroke risk. For DOAC-treated, treatment switch increased stroke risk, while being adherent had a protective effect. Men, antidiabetic treatment or a previous event increased the risk of cerebral bleeding. Receiving direct oral anticoagulants had a protective effect in comparison to vitamin K antagonists. For DOAC-treated, treatment switch increased, and adherence decreased the bleeding risk. Men, people with chronic kidney disease or a previous event posed an increased risk of gastrointestinal bleeding, whereas receiving PPI had a protective effect. For DOAC-treated, switch was associated with a higher bleeding risk. Conclusion: Being men, a previous event and DOAC-switch posed a higher risk for all study outcomes. direct oral anticoagulants had a protective effect against cerebral bleeding in comparison to vitamin K antagonists. Adherence to direct oral anticoagulants resulted in lower risk of stroke and cerebral bleeding. We found no differences in the risk of stroke and gastrointestinal bleeding when we compared direct oral anticoagulants vs. vitamin K antagonists.

Impact of the COVID-19 pandemic on England's national prescriptions of oral vitamin K antagonist (VKA) and direct-acting oral anticoagulants (DOACs): an interrupted time series analysis (January 2019-February 2021)

BACKGROUND

Direct-acting oral anticoagulants (DOACs) were developed as an alternative to warfarin to treat and prevent thromboembolism, including stroke prevention in non-valvular atrial fibrillation patients. The COVID-19 pandemic could increase the risk of stroke and/or the risk of bleeding in patients due to nonadherence or sub/supra-optimal dosing.

OBJECTIVE

To investigate DOAC prescription trends in England's community settings during the complete first wave of COVID-19 pandemic.

METHODS

Descriptive and interrupted time series (ITS) analyses were conducted to examine the prescription patterns of DOACs (dabigatran, rivaroxaban, apixaban and edoxaban) and warfarin for primary care patients in the English Prescribing Dataset from January 2019 to February 2021, with March 2020 as the cut-off point.

RESULTS

A 19% increase in mean DOAC's accompanied with 20% warfarin prescriptions decline was observed. ITS modelling showed an increase in DOAC prescription volume in March 2020 (+7 million items, p = 0.008). The pre-existing upward trend in DOAC prescriptions slowed during the period (-427,000 items, p = 0.007). Apixaban was the most frequently used DOAC and had the largest step-change in March 2020 (+5 million items, p = 0.010). The mean monthly combined cost of DOACs and warfarin was higher during the period. DOAC prescription trends were consistent across England's regions. Conclusion: The overall oral anticoagulants use in this period was lower than expected, indicating a medical needs gap, possibly due to adherence issues. The potential clinical and logistical consequences warrant further study to identify contributing factors and mitigate avoidable risks.

Adherence to rivaroxaban for the treatment of venous thromboembolism-Results from the FIRST registry

BACKGROUND

Medication nonadherence can result in poor clinical outcomes and significant costs to health care providers. When treating venous thromboembolism (VTE), subtherapeutic anticoagulation may contribute to complications such as recurrent VTE or postthrombotic syndrome.

OBJECTIVES

To describe the extent, reasons for, and predictors of nonadherence to rivaroxaban for the treatment of VTE in clinical practice in the United Kingdom reported by participants of the FIRST registry.

PATIENTS/METHODS

The FIRST registry was an observational, multicenter registry reporting on the use of rivaroxaban in routine clinical practice. FIRST registry participants completed an adherence screening questionnaire during their treatment and follow-up.

RESULTS

In total, 1028 participants completed 1660 questionnaires over 2 years. One hundred thirteen of 1028 (11%) reported nonadherence at 28 days (interquartile range, 21-45). Reasons given for nonadherence at 1 month were forgetfulness (8.6% vs 74.7%; P < .001), carelessness (2.7% vs 27.3%; P < .001) or a change in routine (7.4% vs 25.5%; P < .001) reported by adherent and nonadherent participants, respectively. Older age (10-year increments) was the strongest predictor of good adherence (adjusted odds ratio, 1.21; 95% confidence interval, 1.06-1.39; 1 = adherent).

CONCLUSIONS

Overall adherence to rivaroxaban was high, and most nonadherence was unintentional. Identification of those at risk of nonadherence may reduce the risk of VTE recurrence and long-term complications.

The use and adherence of oral anticoagulants in Primary Health Care in Catalunya, Spain: A real-world data cohort study

OBJECTIVE

We aimed to describe sociodemographic, comorbidities, co-medication and risk of thromboembolic events and bleeding in patients with NVAF initiating oral anticoagulants (OAC) for stroke prevention, and to estimate adherence and persistence to OAC.

SETTING

Primary Health Care (PHC) in the Catalan Health Institute (ICS), Catalunya, Spain.

PARTICIPANTS

All NVAF adult patients initiating OAC for stroke prevention in August 2013-December 2015.

METHODS

Population-based cohort study. Persistence was measured in patients initiating OAC in August 2013-December 2014.

DATA SOURCE

SIDIAP, which captures electronic health records from PHC in the (ICS), covering approximately 5.8 million people.

RESULTS

51,690 NVAF patients initiated OAC; 47,197 (91.3%) were naive to OAC and 32,404 (62.7%) initiated acenocoumarol. Mean age was 72.8 years (SD 12.3) and 49.4% were women. Platelet-aggregation inhibitors were taken by 9105 (17.6%) of the patients. Persistence and adherence were estimated up to the end of follow-up. For 22,075 patients, persistence was higher among the non-naive patients [n=258 (61.7%)] than among the naive [n=11,502 (53.1%)]. Adherence was estimated for patients initiating DOAC and it was similar in naive and non-naive patients. Among the naive to DOAC treatment, those starting rivaroxaban showed a highest proportion [(n=360 (80.1%)] of good adherence at implementation (MPR>80%) while patients starting dabigatran were less adherent [n=203 (47.8%)].

CONCLUSIONS

Acenocoumarol was the most frequently prescribed OAC as first therapy in NVAF patients. Non-naive to DOAC showed better persistence than naive. Rivaroxaban showed higher proportion of adherent patients during the implementation phase than apixaban and dabigatran the lowest.

Patient adherence to rivaroxaban in deep vein thrombosis, a cohort study in Switzerland: quantitative results

Background Direct oral anticoagulants (DOACs) have the advantage of being administered orally at a fixed dose without laboratory monitoring, in contrast to the frequent international normalized ratio measurements used to adjust for vitamin K antagonists dosing. Rivaroxaban, has a short half-life. The anticoagulation effect rapidly decreases if medication adherence is suboptimal. Objective The purpose of this quantitative study (called RIVA) is to longitudinally describe adherence to rivaroxaban (implementation and persistence) in patients with deep vein thrombosis (DVT). Setting The community pharmacy of the Center for Primary Care and Public Health (Unisanté), University of Lausanne, Switzerland in collaboration with the angiology division of the Lausanne University Hospital (CHUV). Methods This is an observational study. Patients received rivaroxaban for 3 or 6 months: 15 mg twice a day during the first 3 weeks and then 20 mg once a day until the end of the treatment. Adherence was measured using electronic monitoring. Implementation and adherence were modelled using a generalized estimating equation model. Persistence was represented using a Kaplan-Meier survival curve. Main outcome measure Medication adherence (implementation and persistence). Results Thirty-one consecutive patients were included (68% male, mean age: 47 years old). The collected adherence data consisted of 57 inter-visit phases, 2899 electronic monitoring openings and a median follow-up of 92 days (IQR: 87; 100). Implementation to rivaroxaban was initially high [96.3 (92.8; 98.1)] but decreased during the first 3 weeks, until it reached 89.3 (76.0; 95.6). After the switch from twice a day 15 mg to a once a day 20 mg regimen, implementation increased again and remained stable [95.4 (92.2; 97.3)] for 90 days. Four patients who experienced adverse events discontinued the treatment before the end of the study and were considered non-persistent (clinically appropriate discontinuation). Conclusion Adherence to rivaroxaban in deep vein trombosis is high in persistent patients. Discontinuation is related to rivaroxaban adverse effects/toxicity. Implementation should be reinforced during the twice a day-phase, and this first 3-week experience should help patients and healthcare professionals choose the best timing for the once a day phase.

[Oral anticoagulation in atrial fibrillation: differential therapy with non vitamin K antagonist oral anticoagulants (NOAC) and vitamin K antagonists (VKA)]

BACKGROUND

Non-vitamin K-dependent oral anticoagulants (NOAC) have changed the management of patients with oral anticoagulation. This raises the question of which patients should preferably be anticoagulated with NOAC and which preferably with vitamin K antagonists (VKA). This discussion has so far been insufficiently conducted and often decided on a flat-rate basis in favor of the NOAC.

METHOD

To clarify the question owhich form of anticoagulation - NOAC or VKA - is the best choice for patients with atrial fibrillation, an interdisciplinary team of experts met.

RESULTS AND CONCLUSIONS

The experts discussed essential practical aspects of NOAC and VKA therapy. Based on typical clinical scenarios, they developed assistance, comments and tips on the differentiated use of oral anticoagulants in patients with atrial fibrillation. A criteria served amongst others practicability in daily medical practice, contraindications, side effects and interactions, but also the patient's desire. The advantages and disadvantages of therapy with VKA and NOAC were summarized in a table.

Switching to Another Oral Anticoagulant and Drug Discontinuation Among Elderly Patients With Nonvalvular Atrial Fibrillation Treated With Different Direct Oral Anticoagulants

We compared the risks of switching to another oral anticoagulant (OAC) and discontinuation of direct oral anticoagulants (DOACs) among elderly patients with nonvalvular atrial fibrillation (NVAF) who were prescribed rivaroxaban or dabigatran versus apixaban. Patients (≥65 years of age) with NVAF prescribed DOACs (January 1, 2013 to September 30, 2017) were identified from the Humana research database and grouped into DOAC cohorts. Cox regression analyses were used to evaluate whether the risk for switching to another OAC or discontinuing index DOACs differed among cohorts. Of the study population (N = 38 250), 55.9% were prescribed apixaban (mean age: 78.6 years; 49.8% female), 37.3% rivaroxaban (mean age: 77.4 years; 46.7% female), and 6.8% dabigatran (mean age: 77.0 years; 44.0% female). Compared to patients prescribed apixaban, patients prescribed rivaroxaban (hazard ratio [HR]: 2.08; 95% confidence interval [CI], 1.92-2.25; P < .001) or dabigatran (HR: 3.74; 95% CI, 3.35-4.18, P < .001) had a significantly higher risk of switching to another OAC during the follow-up; compared to patients prescribed apixaban, the risks of discontinuation were also higher for patients treated with rivaroxaban (HR: 1.10; 95% CI, 1.07-1.13, P < .001) or dabigatran (HR: 1.29; 95% CI, 1.23-1.35, P < .001).

How I manage anticoagulant therapy in older individuals with atrial fibrillation or venous thromboembolism

Anticoagulant therapy is the most effective strategy to prevent arterial and venous thromboembolism, but treating older individuals is challenging, because increasing age, comorbidities, and polypharmacy increase the risk of both thrombosis and bleeding. Warfarin and non-vitamin K antagonist oral anticoagulants are underused and often underdosed in the prevention of stroke in older patients with atrial fibrillation because of concerns about the risk of bleeding. Poor adherence to anticoagulant therapy is also an issue for older patients with atrial fibrillation and those at risk of recurrent pulmonary embolism. In this review, we present 5 clinical cases to illustrate common challenges with anticoagulant use in older patients and discuss our approach to institute safe and effective antithrombotic therapy.

Comparison of Drug Switching and Discontinuation Rates in Patients with Nonvalvular Atrial Fibrillation Treated with Direct Oral Anticoagulants in the United States

Introduction

Continuous usage of direct oral anticoagulants (DOACs) among nonvalvular atrial fibrillation (NVAF) patients is essential to maintain stroke prevention. We examined switching and discontinuation rates for the three most frequently initiated DOACs in NVAF patients in the USA.

Methods

Patients who initiated apixaban, rivaroxaban, or dabigatran (index event/date) were identified from the Pharmetrics Plus claims database (Jan 1, 2013–Sep 30, 2016, includes patients with commercial and Medicare coverage) and grouped into cohorts by index DOAC. Patients were required to have a diagnosis of NVAF and continuous health plan enrollment for 12 months prior to the index date (baseline period) and at least 3 months during the follow-up period. Drug switching rates to any other DOAC or warfarin and index DOAC discontinuation rate were evaluated separately with descriptive statistics, Kaplan–Meier analysis, and multivariable Cox regression analysis.

Results

Of the NVAF study population (n = 41,864), 37% initiated apixaban (n = 15,352; mean age 62 years), 51% initiated rivaroxaban (n = 21,250; mean age 61 years), and 13% initiated dabigatran (n = 5262; mean age 61 years). During the follow-up period, the unadjusted drug switching rates of patients treated with apixaban, rivaroxaban, and dabigatran were 3.6%, 6.3%, and 11.1%, respectively (p < 0.001 across the three cohorts); while the index DOAC discontinuation rates were 52.8%, 60.3%, and 62.9%, respectively (p < 0.001). After we controlled for differences in patient characteristics, patients treated with rivaroxaban (HR 1.8; 95% CI 1.6–2.0; p < 0.001) and dabigatran (HR 3.4; 95% CI 3.0–3.8, p < 0.001) had a significantly greater likelihood for drug switching than patients treated with apixaban. Also, both rivaroxaban (HR 1.1; 95% CI 1.1–1.2, p < 0.001) and dabigatran (HR 1.3; 95% CI 1.2–1.3, p < 0.001) treated patients were more likely to discontinue treatment.

Conclusion

In the real-world setting, patients with NVAF newly treated with apixaban were less likely to switch or discontinue treatment compared to patients treated with rivaroxaban or dabigatran.

Funding

Pfizer and Bristol-Myers Squibb.

Quality of life with rivaroxaban in patients with non-valvular atrial fibrilation by therapeutic compliance

OBJECTIVE

To assess the quality of life (QOL) with rivaroxaban in patients with non-valvular atrial fibrilation (NVAF) related to therapeutic compliance.

METHODS

Prospective, longitudinal, multicenter study was developed in 160 Spanish primary or specialized care centers. We included 412 patients treated with rivaroxaban, prescribed for stroke prevention. Three visits were conducted: baseline, 6 and 12 months. Compliance was measured by electronic monitoring systems. QOL was measured by a specific questionnaire. We calculated the percentage of compliance means, the percentage of daily compliers and the score of QOL.

RESULTS

Three hundred and seventy patients finished the study (mean age 75.19 SD: 7.5 years). Daily compliance was 83.5% (CI 78.53-88.57%) (n = 309) and 80% (CI 74.65-85.35%) at 6 and 12 months, respectively. Average QOL rating was 112.85 (SD 29.31) in non-compliant and 111.80 (SD 29.31) in the compliant group (p = Not significant), and after 12 months of 124.67 (SD 30.78) and 83.47 (SD 26.44), respectively (p < 0.0001), with a decrease in the score compliers (p < 0.01) and an increase in non-compliant group (p < 0.05). A higher number of drugs consumed, as well as the number of diseases/conditions suffered, the older age of the patients and having been previously treated with VKA were associated with a higher overall score (worse QOL).

CONCLUSIONS

QOL in NVAF patients treated with rivaroxaban improved significantly over the study group at the expense of compliers. A worse QOL was associated with pluripathology, polymedication, older patients and previous treatment with VKA.

Therapeutic compliance with rivaroxaban in preventing stroke in patients with non-valvular atrial fibrillation: CUMRIVAFA study

OBJECTIVE

To assess compliance with treatment with rivaroxaban in patients with non-valvular atrial fibrillation.

METHODS

Prospective, longitudinal, multicenter study, developed in 160 Spanish primary or specialized care centers. We included 412 patients treated with rivaroxaban, prescribed for stroke prevention. Three visits were conducted: baseline, 6 and 12 months. Compliance was measured by using electronic monitors (MEMSs) that use a digital record in the form of a microchip in the lid of the drug container that automatically controls its opening and registers the time and date of the opening. We calculated the average compliance percentage (CP), global and daily compliance. We considered compliance to be when CP was 80-100%.

RESULTS

Three hundred and seventy patients ended the study (mean age 75.19, SD: 7.5 years). Global compliance was 84.1% (CI = 79.21-88.99%) and 80.3% (CI = 74.98-85.62%) after 6 and 12 months respectively. Daily compliance was 83.5% (CI = 78.53-88.57%) and 80% (CI = 74.65-85.35%) at 6 and 12 months. Significant differences in the CP between 6 and 12 months were observed. Global CP was 90.77% after 6 months and 89.65% at the end of the study. Daily CP was 90.14% and 87.66% at 6 and 12 months. There were significant CP differences between 6 and 12 months. Non-compliance was associated with a higher number of concomitant diseases, number of drugs taken and weight.

CONCLUSIONS

The percentage of compliance with rivaroxaban was high. A profile of variables that need to be modified in current medical practice, associated with non-compliance, was detected.